6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of April 2025

Commission File Number: 001-15214

TransAlta Corporation (Translation of registrant's name into English)

Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1 (Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F. Form 20-F [   ]      Form 40-F [ X ]

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

EXHIBIT INDEX

EdgarFiling EXHIBIT 99.1

TransAlta Declares Dividends

CALGARY, Alberta, April 23, 2025 (GLOBE NEWSWIRE) -- The Board of Directors of TransAlta Corporation (TSX: TA) (NYSE: TAC) declared the following quarterly dividend on its Cumulative Redeemable Rate Reset First Preferred Shares for the period starting from and including March 31, 2025, up to but excluding June 30, 2025:

* Please note the quarterly floating rate on the Series B and Series D Preferred Shares will be reset every quarter.

All currency is expressed in Canadian dollars (unless otherwise noted). When the dividend payment date falls on a weekend or holiday the payment is made the following business day.

About TransAlta Corporation:

TransAlta owns, operates and develops a diverse fleet of electrical power generation assets in Canada, the United States and Australia with a focus on long-term shareholder value. TransAlta provides municipalities, medium and large industries, businesses and utility customers with affordable, energy efficient and reliable power. Today, TransAlta is one of Canada’s largest producers of wind power and Alberta’s largest producer of thermal generation and hydro-electric power. For over 114 years, TransAlta has been a responsible operator and a proud member of the communities where we operate and where our employees work and live. TransAlta aligns its corporate goals with the UN Sustainable Development Goals and the Future-Fit Business Benchmark, which also defines sustainable goals for businesses. Our reporting on climate change management has been guided by the International Financial Reporting Standards (IFRS) S2 Climate-related Disclosures Standard and the Task Force on Climate-related Financial Disclosures (TCFD) recommendations. TransAlta has achieved a 70 per cent reduction in GHG emissions or 22.7 million tonnes CO2e since 2015 and received an upgraded MSCI ESG rating of AA.

For more information about TransAlta, visit our web site at transalta.com .

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